“Glue addresses” in networking

Imagine this scenario.  You have bought an IP or DIA circuit from someone that is going to provide your network with bandwidth.  Typically this company will make the connection, IP wise, over a /30 or even a /29 of IP space.  I have called this the “glue address” for many years.  This is the IP address that binds (the glue reference) you to the other provider’s network. They can route you IP blocks over that glue address or you can establish BGP across it, but it is the static address which binds the two networks together.

Some network folks call this a peering address.  This isn’t wrong but can infer you are doing BGP peering across the address.  You aren’t always doing BGP across the glue address.

#routinglight #packetsdownrange

Noction: BGP in Large Networks

Are you running a large scale BGP network? Need some tips and help on what to optimize and what your next steps to optimize your setup?

Using iBGP with loopback addresses
Making sure all routers know next hop and loopback addresses
Whether to use route reflectors rather than an iBGP full mesh
Where to originate prefixes
Where and how to filter announcements

Using BGP in large scale networks and how to get the most out of it. Paper by Noction

BGP Monitoring RFC 7854

https://tools.ietf.org/html/rfc7854

   This document defines the BGP Monitoring Protocol (BMP), which can be
   used to monitor BGP sessions.  BMP is intended to provide a
   convenient interface for obtaining route views.  Prior to the
   introduction of BMP, screen scraping was the most commonly used
   approach to obtaining such views.  The design goals are to keep BMP
   simple, useful, easily implemented, and minimally service affecting.
   BMP is not suitable for use as a routing protocol.

BGP Confederations

In network routing, BGP confederation is a method to use Border Gateway Protocol (BGP) to subdivide a single autonomous system (AS) into multiple internal sub-AS’s, yet still advertise as a single AS to external peers. This is done to reduce the number of entries in the iBGP routing table.  If you are familiar with breaking OSPF domains up into areas, BGP confederations are not that much different, at least from a conceptual view.

And, much like OSPF areas, confederations were born when routers had less CPU and less ram than they do in today’s modern networks. MPLS has superseded the need for confederations in many cases. I have seen organizations, who have different policies and different admins break up their larger networks into confederations.  This allows each group to go their own directions with routing policies and such.

if you want to read the RFC:https://tools.ietf.org/html/rfc5065